<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>demo1</title>

    <!-- <style>
        div{
            color: aqua;
        }
    </style> -->

    <link rel="stylesheet" href="style.css">
</head>
<body>
    <div>hello</div>
    <div class="one">
        <h3>23322</h3>
    </div>
    <div class="two">
        <h3>32434</h3>
        box-sizing:border-box;
    </div>
    <!-- <div class="three">333</div>
    <div class="four">444</div>
    <div>1111111<span class="two">2222222</span>1111111</div>
    <div id="mmm">duwenud</div>

    <style>
        #mmm{
            color: black;
        }
        .one{
            color: aliceblue;
        }
        .two{
            color: antiquewhite;
        }
        .three{
            color: aqua;
        }
        .four{
            color: aquamarine;
        } -->
    <!-- </style> -->

    <style>
        *{
            box-sizing: border-box;
            margin-left: auto;
            margin-right: auto;
        }
        .one h3{
            color: aliceblue;
            color: rgb(255,0,0);

        }
        .two h3{
            color: aqua;
        }
    </style>
</body>
</html> 